A cosmological model in Weyl$ndash$Cartan spacetime: II. Magnitude-redshift relation

Puetzfeld, Dirk

doi:10.1088/0264-9381/19/16/316

Cited by 28 publications

(15 citation statements)

References 29 publications

(75 reference statements)

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“…The Weyl geometry can be naturally extended to include the torsion. The resulting geometry is called the Weyl-Cartan geometry, and it was widely studied from both mathematical and physical points of view [87][88][89][90][91][92][93][94][95]. Torsion was included in the geometric framework of the Weyl-Dirac theory in [96][97][98], leading to an action integral from which one can construct a general relativistic massive electrodynamics, gauge covariant in the sense of Weyl.…”

Section: Introductionmentioning

confidence: 99%

f(Q, T) gravity

et al. 2019

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We propose an extension of the symmetric teleparallel gravity, in which the gravitational action L is given by an arbitrary function f of the non-metricity Q and of the trace of the matter-energy-momentum tensor T , so that L = f (Q, T). The field equations of the theory are obtained by varying the gravitational action with respect to both metric and connection. The covariant divergence of the field equations is obtained, with the geometry-matter coupling leading to the nonconservation of the energy-momentum tensor. We investigate the cosmological implications of the theory, and we obtain the cosmological evolution equations for a flat, homogeneous and isotropic geometry, which generalize the Friedmann equations of general relativity. We consider several cosmological models by imposing some simple functional forms of the function f (Q, T), corresponding to additive expressions of f (Q, T) of the form f (Q, T) = α Q + βT , f (Q, T) = α Q n+1 + βT , and f (Q, T) = −α Q −βT 2. The Hubble function, the deceleration parameter, and the matter-energy density are obtained as a function of the redshift by using analytical and numerical techniques. For all considered cases the Universe experiences an accelerating expansion, ending with a de Sitter type evolution. The theoretical predictions are also compared with the results of the standard CDM model.

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Section: Introductionmentioning

confidence: 99%

f(Q, T) gravity

et al. 2019

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“…Weyl's geometry can be extended naturally to include torsion. The corresponding geometry is called the Weyl-Cartan geometry, and it was extensively studied from both physical and mathematical points of view [43][44][45][46][47][48][49][50][51]. For a review of the geometric properties and of the physical applications and of the Riemann-Cartan and Weyl-Cartan space-times see [52].…”

Section: Introductionmentioning

confidence: 99%

Weyl type f(Q, T) gravity, and its cosmological implications

et al. 2020

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We consider an f(Q, T) type gravity model in which the scalar non-metricity $$Q_{\alpha \mu \nu }$$Qαμν of the space-time is expressed in its standard Weyl form, and it is fully determined by a vector field $$w_{\mu }$$wμ. The field equations of the theory are obtained under the assumption of the vanishing of the total scalar curvature, a condition which is added into the gravitational action via a Lagrange multiplier. The gravitational field equations are obtained from a variational principle, and they explicitly depend on the scalar nonmetricity and on the Lagrange multiplier. The covariant divergence of the matter energy-momentum tensor is also determined, and it follows that the nonmetricity-matter coupling leads to the nonconservation of the energy and momentum. The energy and momentum balance equations are explicitly calculated, and the expressions of the energy source term and of the extra force are found. We investigate the cosmological implications of the theory, and we obtain the cosmological evolution equations for a flat, homogeneous and isotropic geometry, which generalize the Friedmann equations of standard general relativity. We consider several cosmological models by imposing some simple functional forms of the function f(Q, T), and we compare the predictions of the theory with the standard $$\Lambda $$ΛCDM model.

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“…21 . The group of Dereli, Tucker, and Wang 17,58,59 applied such theories to the dark matter problem, inter alia, Minkevich et al 33,37,34,35,36 , Puetzfeld et al 48,49,50,51 , and Babourova & Frolov 3,2,4 mainly to cosmological solutions. New exact solutions were found, amongst others, by Vassiliev & King 31,60,61,43 .…”

Section: Introductionmentioning

confidence: 99%

Rotating Black Holes in Metric-Affine Gravity

Baekler

Hehl

2006

Int. J. Mod. Phys. D

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Within the framework of metric-affine gravity (MAG, metric and an independent linear connection constitute spacetime), we find, for a specific gravitational Lagrangian and by using prolongation techniques, a stationary axially symmetric exact solution of the vacuum field equations. This black hole solution embodies a Kerr-deSitter metric and the post-Riemannian structures of torsion and nonmetricity. The solution is characterized by mass, angular momentum, and shear charge, the latter of which is a measure for violating Lorentz invariance. file Baekler/Magaxi13.tex

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A cosmological model in Weyl$ndash$Cartan spacetime: II. Magnitude-redshift relation

Cited by 28 publications

References 29 publications

f(Q, T) gravity

f(Q, T) gravity

Weyl type f(Q, T) gravity, and its cosmological implications

Rotating Black Holes in Metric-Affine Gravity

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